Allow symfony/console ^4.0

Author: joostfaassen

composer.json

@@ -13,7 +13,7 @@
     "bin": ["bin/dbtk-schema-loader"],
     "minimum-stability": "stable",
     "require": {
-        "symfony/console": "^2.4|^3.0",
+        "symfony/console": "^2.4|^3.0|^4.0",
         "doctrine/dbal": "~2.5",
         "linkorb/connector": "~1.0"
     },